1. Field of the Invention
The invention relates to oral products for promoting health in the oral cavity.
2. The Related Art
Known oral products take the form of mouthwashes and dentifrices, the latter including paste and gel compositions. A variety of active agents have been used in such products to inhibit the growth of dental plaque which is composed of bacteria. Inhibition of dental plaque and its removal from teeth is not only cosmetically important, but is beneficial for prevention of dental caries, tartar formation and gingivitis.
Copper compounds have long been employed as antibacterial agents in oral products. U.S. Pat. No. 3,065,139 (Ericsson et al) reports a toothpaste comprising ascorbic acid, sodium percarbonate and a copper catalyst. U.S. Pat. No. 3,681,492 (Kotzbauer) also reports combinations of ascorbic acid with catalytic amounts of copper. Further improvements in the ascorbic acid/copper system have been disclosed in co-pending U.S. patent application Ser. No. 07/286,596 (Bird).
Formulating with copper is often difficult because of stability or bioavailability problems. U.S. Pat. No. 4,332,791 (Raaf et al) discloses that antimicrobial activity is seriously reduced where the abrasive is other than silica. Anti-plaque activity with a variety of metal ions, including copper, has reportedly been achieved by incorporation of tetradecylamine. See EP 0 011 663 (Ritchey).
Another substance which has been linked to oral health is that of sodium bicarbonate. Effectiveness of bicarbonate may be attributed to its abrasive character, but it also has been implicated in chemically inhibiting plaque, most often in coordination with hydrogen peroxide. The synergistic effect between hydrogen peroxide and bicarbonate has been widely promoted by Keyes through such articles as "Periodontics and Oral Hygiene", January 1987, pages 51-56.
U.S. Pat. No. 4,487,757 (Kiozpeoplou) discloses a toothpaste that physically segregates sodium bicarbonate from acidic ingredients to prevent contact therebetween prior to usage. U.S. Pat. No. 4,849,213, U.S. Pat. No. 4,687,663 and U.S. Pat. No. 4,528,180, all to Schaeffer, describe systems which house sodium bicarbonate separate from other components of the composition that may co-react therewith.
Based on our experiments and the known art, it is evident that oral compositions containing copper and/or sodium bicarbonate require special measures to ensure adequate storage stability and full bioavailability of actives when dispensed.
Accordingly, it is an object of the present invention to provide a bicarbonate and copper-containing oral composition that maintains stability of the bicarbonate and bioavailability of the copper even after prolonged storage.
This and other objects of the present invention will become more readily apparent upon consideration of the more detailed description and Examples which follow.